/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
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 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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package org.hisp.dhis.artemis.audit.configuration;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.collect.ImmutableMap;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.hisp.dhis.audit.AuditScope;
import org.hisp.dhis.audit.AuditType;
import org.hisp.dhis.external.conf.ConfigurationKey;
import org.hisp.dhis.external.conf.DhisConfigurationProvider;
import org.springframework.stereotype.Component;

/**
 * Configures the Audit Matrix based on configuration properties from dhis.conf
 *
 * <p>This configurator uses properties with prefix "audit.". Each property prefixed with "audit."
 * must match the (lowercase) name of an {@see AuditScope} and must contain a semi-colon list of
 * valid {@see AuditType} names: (READ;UPDATE;...).
 *
 * <p>Example:
 *
 * <p>audit.tracker=CREATE;READ;UPDATE;DELETE
 *
 * <p>Misspelled entries are ignored, and the specific type is set to false. Missing {@see
 * AuditScope} are replaced with all-false types. To disable Auditing completely, simply do not
 * declare any audit.* property in dhis.conf
 *
 * @author Luciano Fiandesio
 */
@Component
public class AuditMatrixConfigurer {
  private final DhisConfigurationProvider config;

  private static final String PROPERTY_PREFIX = "audit.";

  private static final String AUDIT_TYPE_STRING_SEPAR = ";";

  /**
   * Default Audit configuration: CREATE, UPDATE and DELETE operations are audited by default. Other
   * Audit types have to be explicitly enabled by the user
   */
  private static final Map<AuditType, Boolean> DEFAULT_AUDIT_CONFIGURATION =
      ImmutableMap.<AuditType, Boolean>builder()
          .put(AuditType.CREATE, true)
          .put(AuditType.UPDATE, true)
          .put(AuditType.DELETE, true)
          .put(AuditType.READ, false)
          .put(AuditType.SEARCH, false)
          .put(AuditType.SECURITY, false)
          .build();

  public AuditMatrixConfigurer(DhisConfigurationProvider dhisConfigurationProvider) {
    checkNotNull(dhisConfigurationProvider);

    this.config = dhisConfigurationProvider;
  }

  public Map<AuditScope, Map<AuditType, Boolean>> configure() {
    Map<AuditScope, Map<AuditType, Boolean>> matrix = new HashMap<>();

    for (AuditScope value : AuditScope.values()) {
      Optional<ConfigurationKey> confKey =
          ConfigurationKey.getByKey(PROPERTY_PREFIX + value.name().toLowerCase());

      if (confKey.isPresent() && !StringUtils.isEmpty(config.getProperty(confKey.get()))) {
        String[] configuredTypes = config.getProperty(confKey.get()).split(AUDIT_TYPE_STRING_SEPAR);

        Map<AuditType, Boolean> matrixAuditTypes = new HashMap<>();

        for (AuditType auditType : AuditType.values()) {
          matrixAuditTypes.put(auditType, ArrayUtils.contains(configuredTypes, auditType.name()));
        }

        matrix.put(value, matrixAuditTypes);

      } else {
        matrix.put(value, DEFAULT_AUDIT_CONFIGURATION);
      }
    }

    return matrix;
  }
}
